import path from 'path';
import fs from 'fs';
import MarkdownIt from 'markdown-it';
import mdContainer from 'markdown-it-container';
import { highlight } from '../utils/highlight';
import type Token from 'markdown-it/lib/token';
import type Renderer from 'markdown-it/lib/renderer';

const localMd = MarkdownIt();

interface ContainerOpts {
  marker?: string | undefined;
  validate?(params: string): boolean;
  render?(tokens: Token[], index: number, options: any, env: any, self: Renderer): string;
}

export const mdPlugin = (md: MarkdownIt) => {
  md.use(mdContainer, 'demo', {
    validate(params) {
      return !!params.trim().match(/^demo\s*(.*)$/);
    },

    render(tokens, idx) {
      const m = tokens[idx].info.trim().match(/^demo\s*(.*)$/);
      if (tokens[idx].nesting === 1 /* means the tag is opening */) {
        const description = m && m.length > 1 ? m[1] : '';
        const sourceFileToken = tokens[idx + 2];
        let source = '';
        const sourceFile = sourceFileToken.children?.[0].content ?? '';
        if (sourceFileToken.type === 'inline') {
          source = fs.readFileSync(path.resolve('examples', `${sourceFile}.vue`), 'utf-8');
        }
        if (!source) throw new Error(`Incorrect source file: ${sourceFile}`);
        return `<Demo source="${encodeURIComponent(highlight(source, 'vue'))}" path="${sourceFile}" raw-source="${encodeURIComponent(
          source,
        )}" description="${encodeURIComponent(localMd.render(description))}">`;
      } else {
        return '</Demo>';
      }
    },
  } as ContainerOpts);
};
